The lateral access approach is frequently utilized to deliver interbody fusion cages to the lumbar spine. In comparison to conventional anterior or posterior approaches to the lumbar spine, the lateral approach is thought to minimize posterior and/or anterior tissue damage as well as reduce surgery time, associated blood loss, vascular damage and infection risk.
When the lateral access approach is utilized, the surgeon may use sequential dilation followed by tissue retraction in order to provide a minimally invasive path to the disc space. In addition, neuromonitoring is typically undertaken in order to avoid disturbing nerves residing in the lumbar plexus. In particular, one of the cannulae used in the sequential dilation or the retractor used for retraction may be fitted with an electrode capable of detecting a proximate nerve.
Despite these efforts, there still appears to be a significant incidence of neural deficit associated with the lateral approach to the spine. For example, there appears to be about a 30-35% incidence of transient but severe leg pain in patients undergoing an L4-L5 intervertebral fusion by a lateral approach.
Because of the proximity of the neural elements, in particular the femoral nerve, to the center of the disc space, the transpsoas lateral surgical approach to the L4-L5 disc space will likely cause intraoperative displacement of neural structures from their anatomic course during retractor dilation. Careful attention should be paid to retractor placement and dilation time during transpsoas lateral access surgery, particularly at the L4-L5 disc. Davis, J Bone Joint Surg Am. 2011 Aug. 17; 93(16):1482-7.
U.S. Pat. No. 7,686,839 (Parker) discloses a phototherapy treatment devices include a light emitter that is adapted to be placed in close proximity to a wound for applying light/heat energy to the wound to aid in the healing process. The light emitter may comprise a light guide that receives light from a light source or a light source that is affixed to a substrate used to position the light source over the wound.